<span>We know the change of thermal energy is proportional to the specific heat of the matter, its mass and the change of temperatures, according the following formula:
Q = C*m*(Tf-Ti)
where:
Q is the heat added or removed (in joules, J)
C is the specific heat of the matter, in our case air 1,000 J/(Kg*C)
m is the mass, in our case 50 kg of air
Tf is final temperature
Ti is initial temperature
then:
Q = 1000 * 50 * (30-20) = 500,000 Joules
That means that 500,000 joules need to be added to increase temperature of the room 10 ÂşC (from 20 to 30 ÂşC)</span>
Answer:
Explanation:
Given
Acceleration a = 1.0m/s²
Displacement S = 1.0m
Required
Time t taken by the leaf to displace
Using the equation of motion
S = ut+1/2at²
Substitute
1.0 = 0+1/2(1)t²
1 = t²/2
Cross multiply
t² = 2
t = ±√2
t = 1.41secs
It takes the leaf to 1.41s to displace by 1m upward
Answer:
Force acting on the basketball will be 351.85 N
Explanation:
We have given velocity of baseball is changes from 50 m/sec to 45 m /sec in 0.00135 sec
So initial; velocity of the ball u = 50 m /sec
And final velocity of the ball v = 45 m /sec
Mass of the basketball m = 95 gram = 0.095 kg
Time taken t = 0.00135 sec
From third equation of motion v = u+at
So
a = 3703.70
We have to find the force needed to change the speed of the basketball
According to newtons law force is given by F = ma
So F = 0.095×3703.70 = 351.85 N
Answer:
6.35 m/s
Explanation:
The motion of the salmon is equivalent to that of a projectile, which consists of two independent motions:
- A horizontal motion with constant speed
- A vertical motion with constant acceleration (, acceleration of gravity)
The horizontal velocity of the salmon is given by:
where
u = ? is the initial speed
is the angle of projection
Then the horizontal distance covered by the salmon after a time t is given by
Or equivalently, the time taken to cover a distance d is
(1)
Along the vertical direction, the equation of motion is
(2)
where
is the initial vertical velocity
If we substitute (1) into (2), we get:
We now that in order to reach the breeding grounds, the salmon must travel a distance of
d = 2.02 m
reaching a height of
h = 0.574 m
Substituting these data into the equation and solving for u, we find the initial speed that the salmon must have:
Answer:
The electric force between them if the pieces of grain are 2 cm apart is .
Explanation:
Given:
Charge on one grain,
Charge on another grain,
Separation between them,
Electric force acting between two charges separated by a distance is given as:
Where, is Coulomb's constant equal to .
Now, plug in all the values and solve for .
Therefore, the electric force between them if the pieces of grain are 2 cm apart is .