Answer:
- <u>4s</u>
- <u>50m/s (straight)</u>
Explanation:
I will answer in English.
The translated question is:
- <em>3. In a race whose route is straight, a motorcycle circulates for 30 seconds until it reaches a speed of 162.00km / h. If the acceleration remains the same, how long will it take to travel the remaining 200 meters to pass the finish line and at what speed will it do so?</em>
<h2>Solution</h2>
<u>1. Time</u>
First, you must calculate the acceleration, a, starting from rest (V₀ = 0), with a time fo 30 seconds, and final veloficty, V₁, of 162.00km/h.
Convert 162.00km/h to m/s:
- 162.00km/h × 1,000m/km × 3600s/h = 45m/s
- a = (V₁ - V₀)/t = (45m/s - 0) / (30s) = 1.5m/s²
Now, you can calculate the time to travel 200 meters
The most direct equation is;
Where you know:
Use the quadratic formula with a = 0.75, b = 45, and c = -200
Discard the negative value. The positive value is t = 4.1565s
Round to one significant figure: 4s ← answer
<u>2. Velocity</u>
The speed or magnitude of velocity may be calculated using the equation:
With:
- V₂ = 45m/s + 1.5m/s² × 4.1565s = 51m/s ≈ 50m/s, along the same straight line ← answer
d = distance the bowling ball has fallen = ?
g = acceleration due to gravity acting on the ball by earth = 9.8 m/s²
t = time of fall for the ball = 3.0 s
distance the ball has fallen is given as
d = (0.5) g t²
inserting the above values in the equation above
d = (0.5) (9.8 m/s²) (3.0 s)²
d = (0.5) (9.8 m/s²) (9.0 s²)
d = (4.9 m/s²) (9.0 s²)
d = 44.1 m
hence the distance fallen by the ball comes out to be 44.1 m
Work= force x distance
work= 750 x 2
work =1500
power =work/time
power= 1500/ 0.3
power= 5000W
answer: b. 5000W
Answer: The two places altitudes are: 16.17 m and 40.67 m
Explanation:
Hi!
Lets call z to the vertical direction (z= is ground) . Then the positions of the balloon and the pellet, using the values of the velocities we are given, are:
How do we know the value of t₀? This is the time when the pellet is fired. At this time the pellet position is zero: its initial position. To calculate it we know that the pellet is fired when the ballon is in z = 12m. Then:
We need to know the when the z values of balloon and pellet is the same:
We need to find the roots of the quadratic equation. They are:
To know the altitude where the to objects meet, we replace the time values: