Friction
A sled is pulled at a constant velocity across a horizontal snow surface. If a force of 80 N is being applied to the sled rope at an angle of 53.0º to the horizontal, what is the magnitude of the force of friction of the snow acting on the sled?
48.1 N
Shelia has just arrived at the airport and is dragging her suitcase to the luggage check-in desk. She pulls on the strap with a force of 190 N at an angle of 35 degrees to the horizontal to displace it 45 m to the desk. Determine the work done by Sheila on the suitcase.
7003.7 J
A 78-kg skydiver has a speed of 62 m/s at an altitude of 870 m above the ground. Determine the kinetic energy possessed by the skydiver.
1.5 x 105 J
You push on a 22 kg shopping cart with a force of 6.5 N. If you push for 1.9 s, what is the magnitude of the impulse you deliver to the cart?
12.35 kg m/s
A rubber ball of mass 80.0 g hits a wall at 30.0 m/s and rebounds at 20.0 m/s, calculate its Δ ρ.
625 kg m/s
Basking in the sun, a 1.10 kg lizard lies on a flat rock titled at an angle of 15.0º with respect to the horizontal. What is the frictional force on the lizard?
2.79 N
Renee is out with her friends. Misfortune occurs and Renee and her friends find themselves getting in a workout. They apply a cumulative force of 1080 N to push the car 218 m to the nearest fuel station. Determine the work done on the car.
2.35 x 105 J
A 4357 kg roller coaster car starts from rest at the top of a 36.5 m high track. Determine the speed of the car at the bottom of the track.
26.7 m/s
Three friends push a stalled car and its driver to a nearby service station. Assume the car rolls without friction on a smooth level road. If the car is are rest initially and the three friends give it a combined push of 305 N, what is the impulse of the car and driver after 12 s?
3660 kg m/s
Anna and Noah are doing The Cart and the Brick Lab. They drop a brick on a 2.6 kg cart moving at 2.82 m/s. After the collision, the dropped brick and cart are moving together with a velocity of 1.57 m/s. Determine the mass of the dropped brick.
2.07 kg
Kelsey is sledding with her friends when she decides to separate from her group and go towards a bigger hill. She exerts a 31 N force on the rope of her 3.2 kg sled. The rope makes an angle of 34° with the icy surface. Determine the net force and the acceleration of the sled.
F = 25.7 N
A new conveyor system at the local packaging plan will utilize a motor-powered mechanical arm to exert an average force of 890 N to push large crates a distance of 12 meters in 22 seconds. Determine the power output required of such a motor.
485.5 W
A 250-gram cart starts from rest and rolls down an inclined plane from a height of 0.541 meters. Determine its speed at a height of 0.127 m above the bottom of the incline.
2.85 m/s
A 0.650 kg basketball is flying through space at 6.3 m/s to the right when it collides head-on with a 0.190 kg baseball, traveling at 2.8 m/s to the left. After the collision (which took 0.11 s) the basketball has slowed down to 1.3 m/s to the right. What impulse did the basketball experience due to the collision?
-3.25 kg m/s
A 250 g hockey puck going 40.0 m/s hits a stationary goalie (m = 80.0 kg) right in the middle of the pads and sticks there. At what speed do the goalie and puck move together after the collision? (Assume no friction)
0.12 m/s
A 50 N box is on a ramp that has a slant of 35.0º. The coefficient of friction is 0.3. What is the acceleration of the box down the ramp?
3.21 m/s2
A steel ball has a mass of 4.0 kg and rests on a smooth, level surface. A constant force then acts on it through a distance of 22 m to give it a velocity of 62 m/s. What is the magnitude of the force?
349.4 N
A glider is gliding through the air at a height of 416 meters with a speed of 45.2 m/s. The glider dives to a height of 278 meters. Determine the glider's new speed.
68.9 m/s
During ballistics testing, a bullet is fired into a thick gel to bring it to a stop. A 5.5 g bullet traveling at 325 m/s is brought to a stop in the gel by an average force of 550 N. What amount of time is needed for the bullet to come to rest?
0.00325 s
A 0.200 kg plastic ball moves with a velocity of 0.30 m/s. It collides with a second plastic ball of mass 0.100 kg, which is moving along the same line with a speed of 0.10 m/s. After the collision, both balls continue moving in the same original direction, and the speed of the 0.100 kg ball is 0.26 m/s. What is the new velocity of the first ball?
0.22 m/s
A massive light hangs over the table in Laura’s dining room. The light is supported by four string chains which make an angle of 75.0º with the horizontal. The force in each chain is 35.8 N. Determine the mass of the light.
14.1 kg
An elevator motor lifts 715 kg of mass to the height if the fourth floor of an office building (11.0 meters above ground) at a constant speed in 9.35 seconds. Determine the Power of the motor.
8243.5 W
Megan’s mass is 28 kg. She climbs the 4.8 m ladder of a slide and slides down. If there is no friction, how high above the ground will she be when she reaches a velocity of 2.9 m/s? How fast is she going at the bottom of the slide if there is no friction?
4.37 m
9.7 m/s
A 22 kg basketball is dropped and is moving at 2.09 m/s just before it hits the floor. If the basketball rebounds from the floor at 1.9 m/s and was in contact with the floor for 0.14 s, what is the basketball’s change in momentum? What is the force exerted on the basketball during the collision?
87.78 kg m/s
627 N
A 2.2 kg squirrel is flying at 14 m/s due south when it runs right into a 0.6 kg kiwi going 12.1 m/s due east. The squirrel swallows the kiwi whole. Calculate the velocity of the squirrel and kiwi.
11.3 m/s SE