Your local body shop can repair it easily. If you hit the wall at 25 miles per hour, the damage will be greater, and the repair more difficult. Hit that wall at 90 miles an hour and both you and the car are likely to be totaled. It won't make much difference if the car is a Volvo, a Chevy, or a Mazda. Or if the energy source is a dental X-ray machine or a pile of plutonium.
Radiation works in the same way.
A beam of energy or stream of particles may be of such low speed that nothing much happens. Alpha particles, for example, can be stopped by a thin sheet of onion skin. The amount of energy, or the speed of a radiation beam is called the intensity. Intensity determines how deeply it will penetrate into something, and how much ionization it will cause. In determining the potential to cause harm to humans and animals, we also need to look at the idea of dose and dose-rate.