Answer:
The combined velocity is 8.61 m/s.
Explanation:
Given that,
The mass of a truck, m = 2800 kg
Initial speed of truck, u = 12 m/s
The mass of a car, m' = 1100 kg
Initial speed of the car, u' = 0
We need to find the combined velocity the moment they stick together. Let it is V. Using the conservation of momentum.

So, the combined velocity is 8.61 m/s.
The percentage error in his experimental value is -51.97%.
<h3>What is percentage error?</h3>
This is the ratio of the error to the actual measurement, expressed in percentage.
To calculate the percentage error of the student, we use the formula below.
Formula:
- Error(%) = (calculated value-accepted value)100/(accepted............. Equation 1
From the question,
Given:
- Calculated value = 4.15 g/cm
- accepted value = 8.64 g/cm
Substitute these values into equation 1
- Error(%) = (4.15-8.64)100/8.64
- Error(%) = -4.49(100)/8.64
- Error(%) = -449/8.64
- Error(%) = -51.97 %
Hence, The percentage error in his experimental value is -51.97%.
Learn more percentage error here: brainly.com/question/5493941
4. a poor insulator
If rest other things are kept constant or unchanged then a good conductor can be termed as a poor insulator.
Answer:
so maximum velocity for walk on the surface of europa is 0.950999 m/s
Explanation:
Given data
legs of length r = 0.68 m
diameter = 3100 km
mass = 4.8×10^22 kg
to find out
maximum velocity for walk on the surface of europa
solution
first we calculate radius that is
radius = d/2 = 3100 /2 = 1550 km
radius = 1550 × 10³ m
so we calculate no maximum velocity that is
max velocity = √(gr) ...............1
here r is length of leg
we know g = GM/r² from universal gravitational law
so G we know 6.67 ×
N-m²/kg²
g = 6.67 ×
( 4.8×10^22 ) / ( 1550 × 10³ )
g = 1.33 m/s²
now
we put all value in equation 1
max velocity = √(1.33 × 0.68)
max velocity = 0.950999 m/s
so maximum velocity for walk on the surface of europa is 0.950999 m/s