Answer:
i can't sorry
Explanation:
I didn't really pay attention in that class
Answer:
C. At the instant the ball reaches its highest point.
Explanation:
When a body is thrown up, it tends to come down due to the influence of gravitational force acting on the body. The body will be momentarily at rest at its maximum point before falling. At this maximum point, the velocity of the body is zero and since force acting on a body is product of the mass and its acceleration, the force acting on the body at that point will be "zero"
Remember, F = ma = m(v/t)
Since v = 0 at maximum height
F = m(0/t)
F = 0N
This shows that the force acting on the body is zero at the maximum height.
Answer:
Δ KE = 249158.6 kJ
Explanation:
given data
Truck mass M = 1560 Kg
Truck initial speed, u = 28 m/s
mass of car m = 1070 Kg
initial speed of car u1 = 0 m/s
solution
first we get here final speed by using conservation of momentum that is express as
Mu = (M+m) V .......................1
put here value we get
1560 × 28 = (1560 + 1070 ) V
solve it we get
final speed V = 16.60 m/s
and
Change in kinetic energy will be here
Δ KE = 
.................2
put here value and we get
Δ KE = 
solve it we get
Δ KE = 249158.6 kJ
Answer:
Explanation:
On the Moon :----
1500 x 1.6 = 2400 m /s is initial velocity of bullet .
g = 1.6 m /s²
v = u - gt
0 = 2400 - 1.6 t
t = 1500 s
This is time of ascent
Time of decent will also be the same
Total time of flight = 2 x 1500 = 3000 s
On the Earth : ---
v = u - a₁ t
0 = u - a₁ x 18
u = 18a₁
v² = u² - 2 x a₁ x 2743.2
0 = (18a₁ )² - 2 x a₁ x 2743.2
a₁ = 16.93
For downward return
s = ut + 1/2 a₂ x t²
2743.2 = 0 + .5 x a₂ x 31²
a₂ = 5.7 m /s²
If d be the deceleration produced by air
g + d = 16.93 ( during upward journey )
g - d = 5.7
g = (16.93 + 5.7) / 2
= 11.315 m / s
d = 5.6 m /s²
So air is creating a deceleration of 5.6 m /s².
