Answer:
<h2>
4.25m/s</h2><h2>
E. None of the option is correct</h2>
Explanation:
Using the law of conservation of momentum to solve the problem. According to the law, the sum of momentum of the bodies before collision is equal to the sum of the bodies after collision. The bodies move with the same velocity after collision.
Mathematically.
mu + MU = (m+M)v
m and M are the masses of the bullet and the block respectively
u and U are their respective velocities
v is their common velocity
from the question, the following parameters are given;
m = 20g = 0.02kg
u = 960m/s
M = 4.5kg
U =0m/s (block is at rest)
Substituting this values into the formula above to get v;
0.02(960)+4.5(0) = (0.02+4.5)v
19.2+0 = 4.52v
4.52v = 19.2
Dividing both sides by 4.52
4.52v/4.52 = 19.2/4.52
v = 4.25m/s
Since they have the same velocity after collision, then the speed of the block immediately after the collision is also 4.25m/s
Answer:

Explanation:
I = Hearing intensity = 
A = Area = 
d = Diameter = 7.9 mm
r = Radius = 
Power is given by

t = Time the eardrum is exposed to sound = 1 second
Energy is given by

The energy transferred to the eardrum is 
Gravity has an effect on weight, but not on mass. The mass of the object will be the same on both planets. (choice-C)
Answer:
a)Change in the speed = 1.41 m/s
b)The final speed will be 3.11 m/s
Explanation:
Given that
Acceleration ,a= 4.7 x 10⁻³ m/s²
a)
We know that
v= u + a t
v=final speed ,u=initial speed
t= time ,a= acceleration
Change in the speed
v- u = a t
t= 5 min = 5 x 60 s = 300 s
v- u = 4.7 x 10⁻³ x 5 x 60 m/s
v-u = 1.41 m/s
Change in the speed = 1.41 m/s
b)
Given that
u= 1.7 m/s
v-u = 1.41 m/s
v= 1.7 + 1.41 m/s
v=3.11 m/s
The final speed will be 3.11 m/s
1. In construction. When constructing roads, building
2. In Engineering, when engineering we use physics such as calculations.
3. At home
4. In industries, industries use chemicals and so on.
5. In tailoring, we use the knowledge of physics like when sowing.
6. In carpentry, we use calculations.
7. In Hospitals, we use physics we balancing
8. In Sites, we use energy.