Problem 2 (10 pts) A truck travels on a straight road with constant velocity of

Question

Problem 2 (10 pts) A truck travels on a straight road with constant velocity of 15 m/s. Suddenly the driver applies the brakes and the truck eventualy stops after traveling a distance of 50 meters Find a) the acceleration of the car, b) how long did it take the truck to stop after the driver applied the brakes? Problem 3 (11 pts) A ball weighs 98 N on the surface of the earth and 16 N on the surface of the moon. a) What is the gravitational acceleration on the surface of the moon? An astronaut on the surface of the moon throws this ball upwards. It takes 8 seconds for the ball to land back onto her hand. b) What is the initial velocity of the ball? c) What is the maximum height it reaches? Problem 4 (12 pts) A stone is thrown horizontally from the top of a 50 m tall building with an initial speed of 10 m/s. a) How long does it take the stone to reach the ground? b) How far away from the base of the building will the stone land? c) What is the velocity (magnitude and direction) of the stone just before it hits the ground? Problem 5 (7 pts) A river flows with a steady speed 0.5 m/s westwards. A student swims upstream (east- wards) for 100m and then swims back (west wards) 100m to the starting point. If the student can swim at a speed of 1.5 m/s in still water, calculate a) how long will the total swim take if the water was still? b) how long will the total swim take if the river flows as above?

Explanation / Answer

Solving problem 2

Initial velocity =u=15 m/s

Final velocity =v=0

Distance covered=50 m

Using

v*v=u*u +2aS

We got a=-2.25 m/s*s

Let time is t

t=u/a=6.67 s

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---