# Force Problems5/6/7

Every few hundred years most of the plants line up on the same side of the Sun. Calculate the total forces on the Earth due to Venus, Jupiter, and Saturn, assuming all four plants are in line. The masses are Mv = 0.815Me, M3=318Me, Ms=95.1Me and their mean distance from the sun are 108,150, 778 and 1430 million km respectively. What fraction of the sun’s force on the Earth is this?

O . . o o

sun venus mars jupiter saturn

Suppose that a binary-star system consist of two stars equal mass. They are observed to be seperated by 360 million km and take 5.7 Earth years to orbit about a point between them. What is the mass of each?

A jet plan travling 1890km/h (525m/s) pulls out of a dive moving in a arc of radius 6.00km. What is the planes acceleration in g’s.

A coin is placed 11.0 cm from the axis of a rotating turntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on ther turntable until a rate of 36 rpm is reached and the coin slides off. What is the coefficient of static friction between the coin and truntable?

A car in Indianapolis 500 Accerlerates uniformaly from the pit area, giong from rest to 320km/h in a semicircular arc with a radius of 220m. Determine the tangential and radial acceleration of the car when it is half way through the turn, assuming constant tangential acceleration. If the curve were flat, what would the coefficient of static friction be between the tires and the road to provide this acceleration with no slipping or skidding?

A 65.0kg firefighter climbs a flight of stairs 20.0m high. How much work is required?

a. If the KE of a arrow is doubled, by what factor has its speed increased?

b. If its speed is doubled, by what factoe does its KE increase?

By how much does the gravitational potential engery of a 64-kg pole vaulter change if his center of mass rises about 4.0m during the jump?

In the high jump, Fran’s kinetic engery is transformed into gravitational potiential engery without the aid of a pole. With what minimum speed must Fran leave the ground in order to lift her center of mass 2.10m and cross the bar with a speed of 0.70m/s?

How long will it take a 1750-W motor to lift a 315=kg piano to a sixth-story window 10.0m above?

A constant friction force of 25 N acts on a 65-kg skier for 20s what is the skiers chang of velocity?

A 12-kg hammer strikes a nail at a velocity of 8.5m/s and comes to rest in a time interval of 8.0ms (a) What is the impulse given to the nail? (b) What is the average force acting on the nail?

A ball of mass 0.440kg moving east (+x direction) with a speed of 3.30m/s collides head-on with a 0.220-kg ball at rest. If the collision is perfectly elastic, what will be the speed and direction of each ball after the collision?

A 28g rifle bullet travling 230m/s buries itself in a 3.5kg pendulem hanging on a 2.8-m-long string, which makes the pendulem swing upward in a arc. Determine the verticle and horzontal components of the pendulem’s displacement?

Find the center of mass of the three-mass system shown. Specify relatie to the left-hand 1.00kg mass.

1.00kg 1.50kg 1.10kg

0 O 0

< __________0.50m_________><__0.25m___>