Answer:
hey u apply p=mv and 2 are given then calculate thirds value it's a simple do it
Density=mass÷volume
mass=density×volume
mass=2×8=16 g
In this question, one has to carefully understand that the total
number of hours in the day can never be more that 24 hours. based on
this important fact the answer to the question can be very easily
deduced. The only requirement is calculating perfectly.
Number of hours in a day = 24 hours
Percentage of hours of sleep in a day = 33%
Amount of sleep in the day = (33/100) * 24
= 7.92 hours
So 33% of sleep in a day is equal to 7.92 hours. I hope this answer has helped you. In future you can keep the procedure in mind for solving such problems.
Answer: The correct answer is (a).
Explanation:
The potential energy is due to the position of the object.
The kinetic energy is due to the motion of the object.
In the case of a basketball sitting on a shelf, the basketball posses the potential energy due to some height.
In the case of a dog running across a field, a dog has kinetic energy due to its motion.
In a case of a bowling ball rolling down a lane, there is kinetic energy due to the motion of the bowling ball.
In the case of a teenager riding their bike, there is kinetic energy due to the motion of the bike.
Therefore, the correct answer is (a).
Answer:
a) 103.32 m
b) 9.18 s
Explanation:
a) Let's use the knowledge that at the top of its trajectory, the baseball will have a final velocity of 0 m/s.
The acceleration due to gravity is -9.8 m/s², assuming the upwards direction is positive and the downwards direction is negative.
The initial velocity of the baseball is 45 m/s.
We are trying to find the vertical displacement of the baseball, Δx, and we have the variables v, a, and v₀.
Find the constant acceleration equation that contains all four of these variables:
Substitute the known values into the equation.
- (0)² = (45)² + 2(-9.8)Δx
- 0 = 2025 - 19.6Δx
- -2025 = -19.6Δx
- Δx = 103.32
The maximum height of the ball before it falls back down is 103.32 m.
b) Now we want to solve for time t. Find a constant acceleration equation that contains three known variables.
Substitute known values into this equation.
- 0 = 45 + (-9.8)t
- -45 = -9.8t
- t = 4.59183673
Remember that this is only half of the baseball's flight since we are using the final velocity for when the ball is halfway through its trajectory.
To solve for the total time the baseball is in the air, double the time t we solved for.
The baseball is in the air for 9.18 s.
