Momentum is conserved after the collision
Momentum of 2 Kg before collision = 2 * 3 = 6
Momentum of 4 kg before collision = 4 * -3 = -12
so 6 + -12 = 2 * -4 + 4 *x where x is velocity of 4kg marble.
4x - 8 = -6
4x = 2
x = 0.5
Velocity of 4 kg marble is 0.5 m/s after collision
The 2 kg marble will move in the opposite direction to which it was moving before the collision.
The person's horizontal position is given by
and the time it takes for him to travel 56.6 m is
so your first computed time is the correct one.
The question requires a bit of careful reading, and I think there may be a mistake in the problem. The person's vertical velocity at time is
which tells us that he would reach the ground at about . In this time, he would have traveled
But we're told that he is caught by a net at 56.6 m, which would mean that the net cannot have been placed at the same height from which he was launched. However, it's possible that the moment at which he was launched doesn't refer to the moment the cannon went off, but rather the moment at which the person left the muzzle of the cannon a fraction of a second after the cannon was set off. After this time, the person's initial vertical velocity would have been a bit smaller than .
The continent of Antartica is located at the bottom of the world. the South Pole is at its center. Antarctica is the coldest and windiest place on earth. It is covered with ice up to 3 miles thick. Very few plants and animals can survive here, but penguins, fish, and seals live on the coast and in the seas. No people live on Antarctica permanently, but scientists and tourists visit.
It is a conglomeration of rock that collected together over time, and it rotating in a spinning ball that is orbiting a sun that is in the middle of our solar system.
You should look at a picture of the earth from a satellite.<span />
Answer:
D. 2.5 Hz
Explanation:
Frequency = speed of wave / wavelength
= 335 /140 ( from graph)
= 2.4