Mechanics | Relativity Answers

a ball is thrown vertically upward lands on the thrower's hand in 24.5 s. find (a) the time taken by the ball to reach its maximum height, (b) the maximum height attained by the ball, and (c) the initial velocity of the ball

An object with an initial velocity of 20m/s accelerates uniformly at 5m/s² in the direction of its motion for a diatance of 10m.What is the final velocity of the object

A truck traveling at 80 km/hr crashes into a brick wall without rebounding. We want to estimate the magnitude and direction of the force that the wall exerts on the truck. What physics concept will we use to solve this? How do we know? What do we need estimates for to do this? Finish the problem. Show all work.

1)      Madelin fires a bullet horizontally. The rifle is 1.4 meters above the ground. The bullet travels 168 meters horizontally before it hits the ground. What speed did Madelin’s bullet have when it exited the rifle? 

According to an observer on the ground,how many seconds are ticked out by a clock in an airplane moving overhead at 300m/s while the observer's clock ticks out exactly 1000s

according to an observer on earth,a spaceship is going east with a speed of 0.6c and is going to collide head on in 5s with a comet going west at 0.80c.How fast does the spacecraft see the comet to be approaching.According to their clocks,how much time do they have to get out of the way

A lorry of length 16m is travelling at a constant speed of 12ms^-1 in the inside lane of a straight road.

A car of length 4m is initially travelling in the outside lane in the same direction as the lorry and at the same speed. The gap between the two vehicles is 50m.

The car accelerates at 2ms^-2 for 5 seconds, then travels at constant speed for a time and finally decelerates at 2ms^-2 for 5 seconds. Now the car is travelling at the same speed as before, but in front of the lorry and the gap is the same as it was before.

How long did the car take to get from its initial position to its final position?

How far did the car travel in this time?

I will try to draw a diagram, hopefully it comes out good:

initial positions:

car-------------space in between--------Lorry

|---|----------------------------------------|----------|

4m----------50m--------------------------16m

Final positions

Lorry-------space in between--------car

|------------|------------------------------|---|

16m----------50m----------------------4m

a ball thrown from the top of 10m high building with a horizontal speed of 5m/s. (a) calculate the time it takes to drop to the floor. (b) its horizontal displacement at the point when it reaches the floor

1. Why does water pressure increase with depth?

2. Does pressure depend on density?

1. How does density affect pressure in liquids?

2. How does pressure var with depth?