Answer:
statement - 'The work done by friction is equal to the sum of the work done by the gravity and the initial push' is correct.
Explanation:
The statement ''The work done by friction is equal to the sum of the work done by the gravity and the initial push" is correct.
The above statement is correct because, the initial push will tend to slide down the block thus the work done by the initial push will be in the downward direction. Also, the gravity always acts in the downward direction. thus, the work done done by the gravity will also be in the downward direction
here, the downward direction signifies the downward motion parallel to the inclined plane.
Now we know that the work done by the friction is against the direction of motion. Thus, the friction force will tend to move the block up parallel to the inclined plane.
Hence, for the block to stop sliding the the above statement should be true.
Answer:
t = 5 hr
Explanation:
Let kali moves toward east with velocity= V₁= 40 km/ h
Mat moves toward west with velocity = V₂= 50 km/hr
As Klai left one hour earlier = t₁= 1 hr
distance traveled in 1st hour = s₁ = v * t = 40 * 1 = 40 km
Remaining distance = 400 - 40 = 360 km
As they move in the opposite directions:
Relative speed= 40 + 50 = 90 km/ h
s = v * t
⇒ t = s / v
⇒ t₂ = 360 / 90
⇒ t₂ = 4 hr
Total time = t = t₁ + t₂
t = 1 hr + 4 hr
t = 5 hr
Answer:
45.3°C
Explanation:
Heat gained = mass × specific heat × increase in temperature
q = mC (T − T₀)
Given C = 0.128 J/g/°C, m = 94.0 g, q = 305 J, and T₀ = 20.0°C:
305 J = (94.0 g) (0.128 J/g/°C) (T − 20.0°C)
T = 45.3°C
Answer:
y = 43.55 + 2.15t
Explanation:
We were told that in 1983, the per capita consumption was 37.1 pounds, and in 1989 it was 50 pounds.
If we assume t = 0 corresponds to year 1980. Then, for 1983 it will be t = 3 and for 1989,it will be t = 9.
Thus, expressing the information as ordered pairs, we have; (3,37. 1) and (9,50).
Let us now find slope of the linear function:
m1 = (y2 - y1)/(t2 - t1)
m1 = (50 - 37.1)/(9 - 3)
m1 = 2.15
So, we can find the linear equation as;
y - 37.1 = 2.15(t - 3)
y = 37.1 + 2.15t - 6.45
y = 43.55 + 2.15t
Answer:
i. 15.6 m/s
ii. I = 1.44 KNs
Explanation:
The impulse, I, on a body is the product of force applied on it and the time it acts.
i.e I = F x t
Impulse is sometimes expressed as the change in momentum of a body. It is measured in Ns.
i. mass, m, of the player = 92 kg
initial velocity of the player, u = 9.4 m/s
final velocity of the player, v = 6.2 m/s
Since he bounces back on hitting the pole, then the sign of initial and final velocities are of opposite sign.
So that,
change in velocity of the player = final velocity - initial velocity
= 6.2 - (-9.4)
= 6.2 + 9.4
= 15.6 m/s
change in velocity of the player is 15.6 m/s
ii. Impulse, I = m(v - u)
= 92 x 15.6
= 1435.2
Impulse on the player is 1.44 KNs.
