Answer:
1.06 metres per second squared
Explanation:
since friction acts against foward force
20 N - 4 N = 16 N
use Newtons 2nd law F=ma Solve for a:
a= F÷m
= 16 ÷ 15
= 1.06 metres per second squared
Answer:
absorption and insolation.
Explanation:
These days, scientists all over the world use a standard system of measurements. It's the SI or metric system.
What about scientists in the United States, Liberia, and Burma ?
These three countries are the only ones in the world that haven't
adopted the metric system. What do THEY do ?
Easy. When scientists in those countries are off work, they use the
inches, yards, feet, quarts, miles and gallons that everybody around
them is using. But when they go to work, they use the same metric
system that everyone else in the world is using.
Answer:
d. 6.0 m
Explanation:
Given;
initial velocity of the car, u = 7.0 m/s
distance traveled by the car, d = 1.5 m
Assuming the car to be decelerating at a constant rate when the brakes were applied;
v² = u² + 2(-a)s
v² = u² - 2as
where;
v is the final velocity of the car when it stops
0 = u² - 2as
2as = u²
a = u² / 2s
a = (7)² / (2 x 1.5)
a = 16.333 m/s
When the velocity is 14 m/s
v² = u² - 2as
0 = u² - 2as
2as = u²
s = u² / 2a
s = (14)² / (2 x 16.333)
s = 6.0 m
Therefore, If the car had been moving at 14 m/s, it would have traveled 6.0 m before stopping.
The correct option is d
The first law of thermodynamics can be written as

where

is the variation of internal energy of the system

is the amount of heat absorbed by the system

is the work done by the system on the surrounding.
Using this form, the sign convention for Q and W becomes:
Q > 0 --> heat absorbed by the system (because it increases the internal energy)
Q < 0 --> heat released by the system (because it decreases the internal energy)
W > 0 --> work done by the system (for instance, an expansion: when the system expands, it does work on the surrounding, and so the internal energy decreases, this is why there is a negative sign in the formula Q-W)
W < 0 --> work done by the surrounding on the system (for instance, a compression: when the system is compressed, the surrounding is doing work on the system, and so the internal energy of the system increases)