Answer:
Explanation:
given,
angle at which rock is thrown = 60°
rock lands at distance,d = 25 m
initial speed of rock, = ?
In horizontal direction
distance = speed x time
d = v₀ cos 60° t
25 = v₀ cos 60° t............(1)
now,
in vertical direction
displacement in vertical direction is zero
using equation of motion
putting the value of t in equation (1)
v
Hence, the initial speed of the rock is equal to 16.82 m/s
Answer:
Explanation:
1 ) Let the initial horizontal velocity of car be v .
For vertical displacement
vertical displacement h = 21.3 - 2.3 = 19 m
Time taken to fall by 19 m be t
19 = 1/2 x 9.8 t² ( initial downward velocity is zero )
t = 1.97 s
This is also the time taken to cover horizontal displacement of 54 m which is width of river .
horizontal speed v = 54 / 1.97 m /s
v = 27.41 m /s
2 )
At the time of landing on other side , car will have both vertical and horizontal speed .
vertical speed
v = u + gt
= 0 + 9.8 x 1.97 = 19.31 m /s
horizontal speed will remain same as the initial speed = 27.41 m /s
Resultant speed = √ ( 27.41² + 19.31² )
= √ ( 751.3 + 372.87)
= 33.52 m /s
Answer:
Explanation:
Thermal expansion is where materials expand while being heated, causing them to take up more space. Some materials expand more than others. But this all happens due to the motion of tiny little molecules. Temperature is the average kinetic energy of the molecules in a substance.
Thermal expansion is an important consideration for engineering because different materials exhibit changes in size when exposed to heat. Thus, affecting length, width, surface area, volume, shape etc
Answer:
B. interactive
Explanation:
newtons first law is inertia his second is acceleration and third is interactive.
