A 1,500 kg car hits a boulder with a force of 500 N, and the collision takes 0.5 seconds. What is the magnitude of its impulse?
A. 75,000 kg-m/s
B. 50 kg-m/s
C. 250 kg-m/s
D. 750 kg-m/s

C.

250 kg-m/s

Explanation:

Given that the

Mass M = 1,500 kg

Force F = 500 N

Time t = 0.5 seconds

From Newton's second law of motion which state that the rate of change of momentum is proportional to the applied force.

F = mV/t

Ft = mV

Where ft = impulse: the product of time and applied force

Substitutes force and time into the formula

Ft = 500 × 0.5 = 250 Ns

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000