Physics Answers

 A 60 kg woman walking through an alley accidentally broke the heel of her left high-heeled. shoes. Now the woman tries to balance on one heel of a pair of high-heeled shoes. If the heel is circular and has a radius of 0.500 cm

What is the net electric force acting on the +200 uC charge?

The formula h (t) = -4.9t² + 20t+ 80 gives the height (h) above ground in meter (m) of an object thrown at t=0, straight upwards from the top of a tower 80m height.

1)What is the height point reached by the object ?

2) After how many seconds does the object hit the ground?

This question is based on projectile.

6a.A rectangular airstrip measures 34.50 m by 230 m, with the width measured more accurately than the length. Find the area (in m²), taking into account significant figures.

8.a certain car is capable of accelerating at a rate of 0.57 m/s². How long does it take for this car to go from a speed of 30 mi/h to a speed of 40 mi/h?

 s

9.A certain aircraft has a liftoff speed of 129 km/h.(a) What minimum constant acceleration does the aircraft require if it is to be airborne after a takeoff run of 234 m?

 m/s²

(b) How long does it take the aircraft to become airborne?

 s

10.A car accelerates uniformly from rest to a speed of 30.0 mi/h in 11.0 s.

(a) Find the distance the car travels during this time.

 m

(b) Find the constant acceleration of the car.

 m/s²

11. ball is thrown vertically upward with a speed of 30.0 m/s.(a) How high does it rise?

 m

(b) How long does it take to reach its highest point?

 s

(c) How long does the ball take to hit the ground after it reaches its highest point?

 s

(d) What is its velocity when it returns to the level from which it started?

 m/s

An electric lamp rated 200w,240v operates for a time interval of 5 minutes calculate

(a)resistance of the lamp

(b)current flowing through the lamp

(c)electrical energy of the lamp

A spacecraft is in orbit at an altitude of 100 km above the surface of the moon.

What is its speed? Mmoon = 7.34 x 1022 kg and Rmoon = 1.84 x 106 m