Answer:
Explanation:
Friction is defined as a force which acts at the surface of separation between two objects in contact and tends to oppose motion of one over the other.
While kinetic friction is the force that must be overcome so that a body can move with uniform speed over another.
Hence let consider one of the laws of friction which states that: '' Frictional force is independent of the area of the surfaces in contact.''
The value did not vary with area. This is because when calculating the kinetic fiction, the total contact area is not relevant and only the total weight of the system as well of as the block is put into consideration.
Answer:
Explanation:
a ) At constant pressure , work done = P x Δ V
= 200 x 10³ x ( .1 - .04 )
= 12 x 10³ J .
b )
At constant temperature work done
= n RT ln v₂ / v₁
= PV ln v₂ / v₁
= 200 x 10³ x .04 ln .1 / .04
8 x 10³ x .916
= 7.33 x 10³ J .
Answer:
Value of angle between vector a and b is
.
Explanation:
Vectors a and b have scalar product 6.00
Let
be the angle between a and b.

ab cos
= 6 ...(1)
Vectors a and b have magnitude of vector product 9.00

ab sin
= 9 ...(2)
Dividing equation (2) by (1) we get

tan
= 1.5

= 
Thus, value of angle between vector a and b is
.
Answer:

Explanation:
The acceleration of an object is given by:

where
v is the final velocity
u is the initial velocity
t is the time interval it takes for the velocity to change from u to v
For the rocket in this problem,
u = 20,000 m/s
v = 24,000 m/s
t = 55.0 - 5.0 = 50.0 s
Substituting,

Answer:
232.641374 mph
Explanation:
A race car has a maximum speed of 0.104km/s
Let X represent the speed in miles per hour
Therefore the speed in miles per hour can be calculated as follows
1 km/s = 2,236.936292 mph
0.104km/s = X
X = 0.104 × 2,236.936292
X = 232.641374
Hence the speed in miles per hour is 232.641374 mph