FORCE
A 2.00-kilogram object weighs 19.6 newtons on Earth. If the acceleration due to gravity on Mars is 3.71 meters per second2 , what is the object’s mass on Mars?
2.00 kg
a 60.-kilogram rollerskater exerts a 10.-newton force on a 30.-kilogram rollerskater for 0.20 second. What is the magnitude of the impulse applied to the 30.-kilogram rollerskater?
2.0 N•s
A soccer player kicks a ball with an initial velocity of 10. meters per second at an angle of 30.° above the horizontal. The magnitude of the horizontal component of the ball’s initial velocity is
8.7 m/s
A spring with a spring constant of 68 newtons per meter hangs from a ceiling. When a 12-newton downward force is applied to the free end of the spring, the spring stretches a total distance of
0.18 m
Which is a vector quantity?
(1) electric charge
(2) electric field strength
(3) electric potential difference
(4) electric resistance
(2) electric field strength
What is the magnitude of the force needed to keep a 60.-newton rubber block moving across level, dry asphalt in a straight line at a constant speed of 2.0 meters per second?
40. N
A 2.0-kilogram laboratory cart is sliding across horizontal frictionless surface at a constant velocity of 4.0 meters per second east. What will be cart’s velocity after a 6.0-newton westward force acts on it for 2.0 seconds?
2.0 m/s west
A plane flying horizontally above Earth’s surface at 100. meters per second drops a crate. The crate strikes the ground 30.0 seconds later. What is the magnitude of the horizontal component of the crate’s velocity just before it strikes the ground? [Neglect friction.]
100. m/s
A 2 kg block sliding down a ramp from a height of 3.0 meters above the ground reaches the ground with a kinetic energy of 50. joules. The total work done by friction on the block as it slides down the ramp is approximately
9 J
If 60. joules of work is required to move 5.0 coulombs of charge between two points in an electric field, what is the potential difference between these points?
12 V
A 0.50-kilogram object moves in a horizontal circular path with a radius of 0.25 meter at a constant speed of 4.0 meters per second. What is the magnitude of the object’s acceleration?
64 m/s2
A 1000-kilogram car traveling due east at 15 meters per second is hit from behind and receives a forward impulse of 6000 newton-seconds. Determine the magnitude of the car’s change in momentum due to this impulse.
6000 kg(m)/s
A woman with horizontal velocity v1 jumps off a dock into a stationary boat. After landing in the boat, the woman and the boat move with velocity v2. Compared to velocity v1, velocity v2 has
(1) the same magnitude and the same direction
(2) the same magnitude and opposite direction
(3) smaller magnitude and the same direction
(4) larger magnitude and the same direction
(3) smaller magnitude and the same direction
A spring with a spring constant of 80. newtons per meter is displaced 0.30 meter from its equilibrium position. The potential energy stored in the spring is
3.6 J
The current through a 10.-ohm resistor is 1.2 amperes. What is the potential difference across the resistor?
12 V
A 5.0-kilogram box is sliding across a level floor. The box is acted upon by a force of 27 newtons east and a frictional force of 17 newtons west. What is the magnitude of the acceleration of the box?
2.0 m/s2
A 1.20 × 103-kilogram car is traveling east at 25 meters per second. The brakes are applied and the car is brought to rest in 5.00 seconds. Calculate the magnitude of the total impulse applied to the car to bring it to rest.
3.0 × 104 N•s
or
−3.0 × 104 kg•m/s
At the bottom of a hill, a car has an initial velocity of +16.0 meters per second. The car is uniformly accelerated at −2.20 meters per second squared for 5.00 seconds as it moves up the hill. How far does the car travel during this 5.00-second interval?
52.5 m
A toy launcher that is used to launch small plastic spheres horizontally contains a spring with a spring constant of 50. newtons per meter. The spring is compressed a distance of 0.10 meters when the launcher is ready to launch a plastic sphere. Determine the elastic potential energy stored in the spring when the launcher is ready to launch a plastic sphere.
0.25 J
A bolt of lightning transfers 28 coulombs of charge through an electric potential difference of 3.2 × 10^7 volts between a cloud and the ground in 1.5 × 10^−3 second. Calculate the average electric current between the cloud and the ground during this transfer of charge.
1.9 × 10^4 A
or
19 000 A
An object of mass 30 kg is falling in air and experiences a force due to air resistance of 50 newtons.
a. Determine the net force acting on the object
b. calculate the acceleration of the object.
244N
8.13 m/s 2
A rocket sled accelerates to 50 m/s. When the rocket engine stops, the sled skids along its rails. If the coefficient of friction is 0.5, how fast is the sled moving after 2.50 s?
37.75 m/s
A baseball was hit at 45 m/s at an angle of 45° above the horizontal.
a) How long did it remain in the air?
b) How far did it travel horizontally?
a) 6.6 s
b) 2.1 x 102 m
During the Powerhouse lab, Jerome runs up the stairs, elevating his 102 kg body a vertical distance of 2.29 meters in a time of 1.32 seconds at a constant speed.
a. Determine the work done by Jerome in climbing the stair case.
b. Determine the power generated by Jerome.
a. 2.30 x 103 J
b. 1.73 x 103 W
In a circuit, a 100.-ohm resistor and a 200.-ohm resistor are connected in parallel to a 10.0-volt battery. Calculate the equivalent resistance of the circuit.
66.7 Ω