The first opiton is the answer A)<span>Rahul’s weight
</span>
<span>This
is because astronomers have discovered that
the Crab Nebula is 6500 light years from earth. This means it takes 6500 earth years
for light to get from the Crab Nebula to
earth. Therefore, if we are able to observe the
Crab Nebula and beyond it then it means that earth has been in existence for 6500 years and
over. </span>
if there is not a reaction
Answer:
F = 39.36 N
Explanation:
given,
initial speed, u = 38 m/s
final speed, v = 0 m/s
mass of ball = 0.145 Kg
time, t = 0.14 s
Force = ?
using impulse formula
J = change in momentum
J = F x t
m(v - u) = F x t
0.145 x (0 - (-38)) = F x 0.14
F x 0.14 = 5.51
F = 39.36 N
force exerted by the ball is equal to 39.36 N.
Answer:
a) 8.61 m/s, b) 5.73 m
Explanation:
a) During the collision, momentum is conserved.
mv = (m + M) V
(12.5 g) (86.4 m/s) = (12.5 g + 113 g) V
V = 8.61 m/s
b) After the collision, energy is conserved.
Kinetic energy = Work done by friction
1/2 (m + M) V² = F d
1/2 (m + M) V² = N μk d
1/2 (m + M) V² = (m + M) g μk d
1/2 V² = g μk d
d = V² / (2g μk)
d = (8.61 m/s)² / (2 × 9.8 m/s² × 0.659)
d = 5.73 m
Notice we used the kinetic coefficient of friction. That's the friction when an object is moving. The static coefficient of friction is the friction on a stationary object. Since the bullet/block combination is sliding across the surface, we use the kinetic coefficient.
