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How far does a car travel if it starts at 44m/s and accelerates at -6.0m/s^2 until it reaches a speed of 22m/s?
d=121m
An apple is dropped out a window and falls to the ground. If air resistance is negligible, how long does it take the apple to fall 40 meters?
2.86s
The student drops a ball from rest and uses a radar gun to find the ball’s velocity after 4 s. Neglecting air resistance, what is the expected final velocity of the ball?
Vf=-39.24 m/s
A 70 kg man enters an elevator. The elevator accelerates up at 7.0m/s^2 for the first 7 seconds. What is the net force on the man?
Fnet=490N
A skier skis straight down a slope starting at 10m/s. She accelerates down the hill at 4.5m/s^2 for 20 seconds. How far does she travel?
d=1100m
What is the normal force of a 2000 kg truck at rest on a level surface?
19600 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 watts
A sled is pulled in the snow with a constant velocity by applying a 12 N force in the horizontal direction. The weight of the sled is 900 N. a)What is the force of friction between the sled and the snow? b)What is the coefficient of kinetic friction between the sled and the snow?
a) Ff=12N b) u=.013
Find the force of attraction between a 70 kg man and 11 kg man sitting 2 meters away from each other.
Fg=1.28 x 10^-8
What is the force needed to stretch a spring with a constant of 82 N/m a length of .08 m?
Fs=6.56N
A ski jumper has a mass of 59.6 kg. He is moving with a speed of 23.4 m/s at a height of 44.6 meters above the ground. Determine the total mechanical energy of the ski jumper.
E = 4.24 E 4 J
A car drives 70 km at 45 degrees North of East and 60 km east. Determine the distance travelled by the car.
130 m
A golf ball is hit with an initial speed of 45 m/s at a angle of 45 degrees above the horizontal. What are the initial horizontal and vertical velocity components?
Vx= 31.82 m/s Vy= 31.82 m/s
If 60 J of work are required to move 15 electrons, what is the voltage?
2.5E19 volts
A boy scout travels 5 km at 37 degrees North of East and 2.7 km west. Determine the displacement of the boy scout.
3.27 km at 66.8 degrees N of E
A 50 kg mass is sitting on a frictionless surface. An unknown constant force pushes the mass for 2 seconds until the mass reaches a velocity of 3 m/s. What was the force acting on the mass?
F = 75 N
A 12000 kg truck is moving at a constant speed of 126 km/hour. It suddenly applied the brakes and stopped in 12 meters. How much work has been done on the truck?
7.34E6 J
A 13 kg block hangs from a spring and stretches the spring 0.11m. How much potential energy is stored in the spring?
k=1159.36 N/m
7.0059 J
Two billiards balls of mass 2 kg roll towards each other. The ball rolling to the right is rolling at 12 m/s and the ball rolling left at 2 m/s. After they collide the first ball rolls to the left at 4 m/s. What is the speed and direction of the other ball after the collision?
1) V2f= 14 m/s
A 110 kg linebacker running at 7.5 m/s hits a stationary 90 kg quarterback. At what speed do they move off together?
Vf= 4.125 m/s
A 6.8-kg toboggan is kicked on a frozen pond, such that it acquires a speed of 1.9 m/s. The coefficient of friction between the pond and the toboggan is 0.13. Determine the distance which the toboggan slides before coming to rest.
force friction = 8.66N
a = 1.27 m/s/s
d = 1.42m
1)Bob runs at 40 m/s off a 200 m high cliff. How long will Bob be in the air for? 2) How far from the base of the cliff does Bob land?
1) t=6.39s 2) d=255.6m
A soccer player kicks a stationary ball giving it a speed of 27 m/s at an angle of 25 degrees to the horizontal. 1) What is the maximum height reached by the ball?
2) What is the balls horizontal and vertical velocity at this max height?
H = 6.64 m
vy = 0
vx = 24.5m/s
A 6 ohm and a 22 ohm resistor are connected in parallel to a 9 volt battery. 1) What is the equivalent resistance? 2) How many electrons will pass through the 6 ohm resistor in 1 second?
1) 4.7 ohms 2) 1.2E19 electrons
1)A 550 kg car travels east across a level straight road at 87 m/s. What will be the car’s velocity after a 40050 newton westward impulse is applied to the car? 2)A 7.5 kg lab cart is accelerated uniformly from rest to a speed of 7.5 m/s in 2.5s. What is the magnitude of the force producing this acceleration?
1) Vf= 14.18 m/s east 2) F= 22.5N