- #1
gakusei_98
- 6
- 0
dear all,
I started to study the physics during this summer holiday, I bought some books and I could not slove below questions which found in the books, I do not know to use which equation is correct...
does anyone experts can help me ?
-----(v=s/t; s=1/2(u+v)t; v=u+at; s=ut+1/2at^2; v^2=u^2+2as)
1. A car starts from rest with a uniform acceleratin of 0.6ms^-2. A second car B starts from the some point, 4 seconds later and follows the same path with an acceleration of 0.9ms^-2. How far will the cars have traveled when B passes A ?
* I think ...u=0m/s a=0.6ms^-2; a=0.9ms^-2 t=4s g=-9.81m/s^2
-----(v=u-gt; s=ut-1/2gt^2; v^2=u^2-2gs)
2. A stone is falling freely, has an instantaneous velocity of 25m/s^-1, having started from rest. Calculate (a) how long it has been falling? (b) how far it has fallen? (c)its velocity after falling for a further 3.5 secnds? (d) the distance it has convered during these 3.5 seconds?
* I think...u=0m/s v=25m/s^-1 t=3.5s g=-9.81m/s^2
3. A tower is 100m high. One body is dropped from the top of the tower, and at the same instant another body is projected vertically upwards from the bottom, and they meet half-way up. Find (a) the initial velocity of the projected body? (b) its velocity when it neets the descending body?
* I think...d or h=100m; d1 or h1=100m/2 g=-9.81m/s^2
4. A rocket leaves its pad vertically with an acceleration of 7.5m/s^-2 which remains constant until the fuel is exhausted after 8 seconds. It then continues to travel freely in the vertical direction. Find (a) the total time taken for the rocket to reach its highest? and (b) the altitude achived?
* I think...u=7.5m/s^-2 t=8 seconds g=-9.81m/s^-2
I started to study the physics during this summer holiday, I bought some books and I could not slove below questions which found in the books, I do not know to use which equation is correct...
does anyone experts can help me ?
-----(v=s/t; s=1/2(u+v)t; v=u+at; s=ut+1/2at^2; v^2=u^2+2as)
1. A car starts from rest with a uniform acceleratin of 0.6ms^-2. A second car B starts from the some point, 4 seconds later and follows the same path with an acceleration of 0.9ms^-2. How far will the cars have traveled when B passes A ?
* I think ...u=0m/s a=0.6ms^-2; a=0.9ms^-2 t=4s g=-9.81m/s^2
-----(v=u-gt; s=ut-1/2gt^2; v^2=u^2-2gs)
2. A stone is falling freely, has an instantaneous velocity of 25m/s^-1, having started from rest. Calculate (a) how long it has been falling? (b) how far it has fallen? (c)its velocity after falling for a further 3.5 secnds? (d) the distance it has convered during these 3.5 seconds?
* I think...u=0m/s v=25m/s^-1 t=3.5s g=-9.81m/s^2
3. A tower is 100m high. One body is dropped from the top of the tower, and at the same instant another body is projected vertically upwards from the bottom, and they meet half-way up. Find (a) the initial velocity of the projected body? (b) its velocity when it neets the descending body?
* I think...d or h=100m; d1 or h1=100m/2 g=-9.81m/s^2
4. A rocket leaves its pad vertically with an acceleration of 7.5m/s^-2 which remains constant until the fuel is exhausted after 8 seconds. It then continues to travel freely in the vertical direction. Find (a) the total time taken for the rocket to reach its highest? and (b) the altitude achived?
* I think...u=7.5m/s^-2 t=8 seconds g=-9.81m/s^-2