Answer:
4°C
Explanation:
Water is densest at 4°C. Since dense water sinks, the bottom of the lake will be 4°C.
Answer:
D, using a spring scale to exert a force on the block. Measure the acceleration of the block and the applied force
Explanation:
For this you would use the net force equation acceleration=net force * mass however you will want to isolate mass so it would be acceleration/ net force to get mass. Then process of elimination comes to play.
Answer:
c. about 1/10 as great.
Explanation:
While jumping form a certain height when we bend our knees upon reaching the ground such that the time taken to come to complete rest is increased by 10 times then the impact force gets reduced to one-tenth of the initial value when we would not do so.
This is in accordance with the Newton's second law of motion which states that the rate of change in velocity is directly proportional to the force applied on the body.
Mathematically:
since mass is constant
when 
then,
the body will experience the tenth part of the maximum force.
where:
represents the rate of change in dependent quantity with respect to time
momentum
mass of the person jumping
velocity of the body while hitting the ground.
Answer:
Explanation:
A motor converts electrical energy to mechanical energy. A current carrying coil is placed between electromagnets. A magnetic force is exerted on the coil which makes it rotate. The direction of current changes twice during the rotation of the coil. An outside source of electric current is used.
Thus, the wrong statement is D. It converts mechanical energy into electrical energy. It is the generator which converts mechanical energy into electrical energy.
Answer:
29.96m/s
Explanation:
Given parameters:
Initial speed = 25.5m/s
Acceleration = 1.94m/s²
Time = 2.3s
Unknown:
Final speed of the car = ?
Solution:
To solve this problem, we are going to apply the right motion equation:
v = u + at
v is the final speed
u is the initial speed
a is the acceleration
t is the time taken
Now insert the parameters and solve;
v = 25.5 + (1.94 x 2.3) = 29.96m/s
